crews closed a lane of traffic on jackson street for the repairs. they expect to finish in three hours. still no word on what caused that break. >>> meanwhile, work has resumed on the central subway project in san francisco shutting down streams once again. stockton street between geary and ellis is closed for the construction. crews had halted their work about 6 weeks ago to make life easier on holiday shoppers. >>> it is the end of an era for the exploratorium in san francisco. this is the very last day for fans young and old to geek out at its location near the palace of fine arts. let's go live to cbs 5 reporter anne makovec. she is live outside the museum with the big moving plans and big lines behind you. >> reporter: that's a long line behind me and you can't even see half of it. there's probably 100 people. the line is around the block right now. 2,000 people have been here already and they are expecting 5,000 by the end of the day because the exploratorium is free today. everybody is coming here to celebrate and reminisce. the sounds of wid